1. Technical Field
The present invention relates to a technology for ejecting liquid from an ejection head.
2. Related Art
A liquid ejecting apparatus configured to eject liquid such as ink from an ejection head having minute ejection nozzles is known. Such a liquid ejecting apparatus is generally designed so as to eject liquid from ejection nozzles onto a printing medium such as a printing sheet while transporting the printing medium in the horizontal direction. Therefore, components which constitute the liquid ejecting apparatus are arranged horizontally, and hence the liquid ejecting apparatus requires a large surface area for installation. Accordingly, a configuration in which liquid is ejected onto the printing medium while transporting the medium in the vertical direction (so-called, vertical type) has been employed. When the liquid ejecting apparatus is of the vertical type, the components of the liquid ejecting apparatus can be arranged in the vertical direction. Therefore, reduction of the surface area for installation of the liquid ejecting apparatus is achieved.
However, the probability of falling over of the liquid ejecting apparatus increases with a decrease in surface area for installation. In the case of a normal liquid ejecting apparatus which is not of the vertical type, the posture of the liquid ejecting apparatus is changed from the normal posture (the posture taken when ejecting liquid) while being carried. When the posture of the liquid ejecting apparatus is changed from the normal posture, the state of the ejection head may change. Therefore, a configuration in which detection of the inclination of the liquid ejecting apparatus is enabled using an acceleration sensor attached to the liquid ejecting apparatus (JP-A-2005-271384), and maintenance of the ejection head is performed when it is determined that the liquid ejecting apparatus has fallen from an output from the acceleration sensor has been contemplated.
However, the change in posture of the liquid ejecting apparatus may occur not only in a state in which electric power is supplied to the liquid ejecting apparatus (that is, when the power is ON), but also in a state in which the electric power supplied to the liquid ejecting apparatus is shut down (when the power is OFF). Since the acceleration sensor cannot be used in the state in which the power is OFF, there arises a problem that determination of whether or not the posture of the liquid ejecting apparatus has changed from the normal posture during the period when the power was OFF cannot be performed.